In previously disclosed driving arrangements for the mechanical furling and unfurling of sails on boats, the arrangement is bulky because it is attached either longitudinally to the driving device, i.e. in such a way that an hydraulically or electrically powered motor, for example, is connected to the screw of a worm gear at one end, or laterally because of drive motors and worm gear screws arranged in parallel with one another at the transmission device. The presence of such projecting parts close to the mast and/or stays on boats has been found to be a major disadvantage, since they have often presented the risk of injury to crew members as they pass by. The mass of the arrangement can also be considerable.
U.S. Pat. No. 3,608,511 shows a boom turning device comprising a worm gear mechanism in which a crank hole in a worm screw is intended to accommodate the end of a crank for driving the arrangement when turning the sails, whilst GB A 2,226,800 shows a sail driving arrangement which, likewise with a driving unit in the form of an electric motor, is accommodated with one part in a worm gear screw, more specifically in the gear casing.
The principal object of the present invention is thus, in the first instance, to make available a solution to this problem using simple and effectively functioning means.
Said object is achieved by means of an arrangement in accordance with the present invention, which is characterized essentially in that the driving device, which consists of an hydraulic motor, is capable of being accommodated with at least one part in an internal space in the screw of the worm gear.